Some Jurassic Osmundaceae from New Zealand . 1 
BY 
EDMUND W. SINNOTT. 
With Plate XXXVII. 
HE vexed question of the morphology of the pith in vascular plants 
-L is still a point of dispute among botanists, but at present there seems 
to be a pretty general agreement of opinion, that in the great majority of 
the Pteridophyta the pith should be regarded as derived from the cortex, 
and as morphologically identical with it. 2 Many anatomists, however, 
contend that in at least two families, the Osmundaceae and the Ophio- 
glossaceae, medullation has been achieved by a different process, the pith 
arising in an intrastelar fashion, and having no morphological connexion 
with the cortex. These two groups of Ferns present more evidence in 
favour of such a view than do any other vascular plants, and the discussion 
of the problem of stelar morphology has to a large extent become centred 
about their structure and phylogenetic history. All new facts concerning 
the anatomy of living or fossil members of these two families are therefore 
of particular interest. 
Dr. A. J. Eames and the writer recently spent some time in New 
Zealand as Frederick Sheldon Travelling Fellows in Botany from Harvard 
University, and were fortunate in securing several petrified stems of 
Osmundites from the Jurassic rocks of the North and South Islands. 
A description of their structure and a discussion of its bearing on the 
morphology of the Osmundaceae is the purpose of the present paper. 
Material was obtained from two localities: one, the Jurassic ‘Fossil 
Forest 5 near Waikawa, Southland, at the extreme southern tip of the 
South Island ; and the other (for a specimen from which the author is much 
indebted to Professor P. Marshall), the Jurassic rocks of Kawhia, North 
Island. The Kawhia material is in an excellent state of preservation 
(PI. XXXVII, Fig. i), whereas that from Waikawa is somewhat compressed, 
and most of its structure, except for the xylem and sclerenchyma, has 
been destroyed (PI. XXXVII, Figs. 2 and 3). 
1 Contributions from the Phanerogamic Laboratories of Harvard University, No. 62. 
2 A few investigators, however, deny the morphological value of the endodermis. 
[Annals of Botany, Vol. XXVIII. No. CXI. July, 1914] 
